I know, this is an odd question but SURELY there is no better place to find out odd names and words.

You know, the chalk lines you see drawn around bodies on the ground, either in life or on the cop shows?

The reason I ask is even odder. I was driving down a street after a light snowstorm, and the shadows of the cars parked along the curb had an odd white trace next to them--exactly like the chalk lines next to dead bodies. I realized the cars weren't dead, it was just the sun melting the snow that wasn't in the shadow of the cars, and some trick of temperatures resulted in a "chalkline" about two inches wide. Still, it made me wonder, WTF do you call those lines?! They must have some kind of proper name, no?